Atomic Desalination

bio6.005.031-19481216

In June 1947, Linus Pauling gave a speech in which he spoke about potential non-military uses for atomic power. One potential use that he mentioned in passing was “atomic desalination.” Pauling hypothesized that nuclear energy could be used to desalinate large amounts of seawater in a cost efficient manner – possibly at a rate of five cents per ton of water – and use it for irrigation purposes in arid climates such as those found in and around Los Angeles.

Pauling was not the first scientist to suggest this possibility but he was the most famous. As a result, rather quickly he began receiving letters inquiring into what he had said. Notably, he received letters from Dr. M.R. Card of the Desert Water Association and Samuel B. Morris, the General Manager and Chief Engineer of the Los Angeles Department of Water and Power.

Card was excited by Pauling’s speech and requested that Pauling come talk more about the subject to the Desert Water Association. Pauling declined as he was about to leave for an eight month stint in England as visiting professor at Oxford. He also wrote that he felt atomic desalination to be a technology that would be a long time in coming because of barriers erected by the U.S. government. Specifically, Pauling observed that the government was hesitant to use atomic power for any non-military use and, as such, fuller exploration of atomic desalination would have to wait until the government relaxed its grip on nuclear technology.

For his part, Morris was curious if Pauling had any specific plans in mind and if he was optimistic, given that atomic desalination held the potential to dramatically alleviate the city’s chronic water problems. He was also concerned about Pauling’s hypothesized cost, writing

…while five cents per ton impresses the layman as a very low cost, actually‚Ķ [this is] a higher cost for undistributed water at sea level than any irrigation water delivered to the land with which I am familiar.

In support of his argument, Morris noted that Los Angeles’ current method of piping water from the Colorado River cost about $15 per acre, while a rate of five cents per ton would actually cost over four times as much, at about $68 per acre. Pauling was in England by that time and never responded to Morris.

Publication Unknown, ca. June 1947.

Publication Unknown, ca. June 1947.

Over a year later, in December 1948, the idea of atomic desalination was again suggested by Dr. Robert J. Fowler, head of the chemistry department at John Hopkins University, during a speech at an alumni function. He and many fellow chemists had come to the conclusion that nuclear energy might be the only economical method of conducting large-scale desalination. He also suggested that, while such a technology was likely many years distant, small supplementary atomic desalination trials “may be imminent.”

Fowler’s proposal was based on experiments that had been run at the Hanford Nuclear Reservation in Washington state. The plan was to insert piles of uranium along an ocean coastline, in the water. The increased temperatures generated by the piles would evaporate the seawater, which would be collected and then recondensed in large distillation plants.

Many scientists were excited about and supportive of this proposed technology. However, numerous others expressed concern that water collected in this way would be utterly lacking in mineral content and would therefore need to be fortified, thus increasing the cost and complexity of the process.

Pauling never showed any increased interest in the subject beyond the periodic comments that he delivered to press in 1948. The rest of the scientific community showed an intense interest, but this lasted only a short time as well. For whatever reason, the idea never really took off and the proposed nuclear desalination projects faded from public awareness.


Artist's rendering of a proposed nuclear desalination plan. (Credit: Oak Ridge National Laboratory)

Artist’s rendering of a proposed nuclear desalination plan. (Credit: Oak Ridge National Laboratory)

The term “nuclear desalination” is still in use today though its meaning differs from Pauling’s and Fowler’s conception. Modern nuclear desalination utilizes “conventional” desalination techniques, but these techniques are powered by nuclear reactors instead of fossil fuel plants. The World Nuclear Association (WNA) reports that the most common method of desalination is reverse osmosis, a method by which water is “driven by electric pumps…through a membrane against its osmotic pressure.”

This process is extremely energy-intensive. According to the WNA, reverse osmosis requires about 6 kilowatt hours of electricity per cubic meter of water. Whether fueled by nuclear power or fossil fuels, the WNA reports that desalination costs about 70-90 cents per cubic meter of water. Noting this, researchers at the Massachusetts Institute of Technology are hoping to increase the effectiveness and decrease the cost of desalination by inventing better filters. Currently they are working on a graphene sheet filter that is one atom thick.  Graphene is a carbon and is a markedly more effective filtering substance than are other alternatives.

In 2007 Dr. Nolan Hertel of the Georgia Institute of Technology wrote in the Atlanta Journal-Constitution that nuclear desalination was more energy efficient and cost effective than was the use of fossil fuel plants. He wrote that Kazakhstan, India, Japan and Russia all have effectively utilized nuclear desalination and that the rest of the world should learn from their example.

Currently, the WNA reports that Australia, India, Israel, Russia, and the United States have functioning nuclear desalination plants. Of note, currently all of the US plants are located on board military aircraft carriers, but the US government is in the process of building plants on land. The WNA also points out that Algeria, China, Egypt, Ghana, Indonesia, Iran, Jordan, Mexico, Oman, Kuwait, Libya, Qatar, Saudi Arabia, Spain, Tunisia, the United Arab Emirates, and the United Kingdom are all in the process of designing or building plants. It is worth mentioning that the Iranian plant project appears to have stalled at the time of this writing.

The International Atomic Energy Agency – a component of the United Nations – is likewise encouraging nuclear desalination plants. The agency has developed a Desalination Economic Evaluation Program (DEEP), which they offer as a free download on their website. DEEP is “a tool made freely available by the International Atomic Energy Agency, which can be used for performance and cost evaluation of various power and water co-generation configurations.”

While the technology of nuclear desalination, as imagined by Pauling and Fowler, never came to pass, it does exist in a different form and appears to be growing. One presumes that Pauling – or at least the 1948 version of him – would be pleased to see nuclear power being used in a peaceful technology that benefits humanity. It remains to be seen, however, whether the technology will prove to be as helpful as he once claimed would be the case.

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